1. Field of the Invention
Apparatuses and methods consistent with the present invention relate to a one-dimensional (1D) spatial light modulator (SLM) and an image output device employing the same, and more particularly, to a transmissive 1D SLM for modulating linear shaped light using an electro-optic effect and an image output device employing the same.
2. Description of the Related Art
In general, 1D SLMs are used for image output devices such as printers or displays, and used to modulate linear shaped light on a pixel-by-pixel basis.
As an example, a laser scanner for a related art laser printer achieves 1D light modulation by rotating a polygon mirror using an electric motor, and scanning laser light onto a mirror surface of the polygon mirror to change the propagation direction of laser light being reflected. However, the laser scanner produces a large amount of audible noise due to the presence of a driving element, and permits little flexibility in selecting alternative designs. Another drawback is that optical components such as the polygon mirror require an additional optical system for compensating for optical aberrations.
As another example of a related art spatial light modulator, a light emitting diode (LED) head includes a plurality of LEDs aligned in a line. A printer using an LED head has been presented in Japanese Patent Application Laid-Open Gazette No. 2000-025265. The LED head controls operation of each LED to expose a photosensitive device, thus functioning as a 1D light modulator. The LED head permits high flexibility in selecting alternative designs and uniform intervals between pixels. However, the LED head has drawbacks in that it is difficult to maintain uniform intensity or lifespan of each LED and it generates a great amount of heat.
As yet another example of a relate art, a grating light valve (GLV) is a Micro-Electromechanical System (MEMS) using diffraction of light. A display device incorporating GLVs has been proposed in U.S. Pat. No. 5,982,553. The GLV modulates light using the fact that a diffraction grating including ribbons is moved by an electrostatic driving force so light incident thereon is diffracted to a varying extent. The GLV has a drawback in that the manufacturing process thereof is complicated. Another drawback is that residual charges are created due to mechanical driving caused by static electricity and sticking occurs due to charge buildup.